We have three free range chickens we got in April. The coop is not ready for them to lay eggs. Yesterday I noticed at night when I went to lock up their coop that only one chicken was inside and the other two were still out huddled together. Next day we let all three chickens out and three hours later only find two. Of course I have considered the fact that a predator got to the chic but also thought maybe she went off to lay her eggs. Would she leave the flock and if so how long would she sit on them unfertilized? Or could she have been sick and the rest of the flock kicked her out?